Sound translating device



May 6, 1941. Q PYE 2,240,576

scum) TRANSLATING DEVICE Filed May 24, 1932 32 /33 3 a6 V, 6 "l'fli'll'il'll'i'b 3 5 330 F IG. 3

INVENT OR.

HAROLD C. PYE

ATTORNEYS Patented May 6, 1941 SOUND rmsm'rmo DEVICE Harold Charles Pye, Oak Park, 111., assignor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application May 24, 1938, Serial No. 209,805

lating devices and more particularly to a winding spool and armature assembly for a sound translating device of the magnetic or sound powered type.

In a telephone transmitter of this type. a magnetic field structure is provided which conventionally comprises a permanent magnet and two sets of adjacent-pole pieces, the adjacent pole pieces of each set being of opposite polarity. A pivotally mounted magnetic armature is associated with the magnetic field structure, the opposite ends of the armature being disposed between the Pole pieces of the respective sets. A sound wave responsive diaphragm is connected and arranged to subject the ends of the armature. to vibratory movements between the pole pieces of the respective sets and corresponding to the sound to be transmitted. A winding or voice coil carried by a winding spool is electromagnetically coupled to the armature, whereby an electromotive force is generated in the winding corresponding to the vibratory movements of the armature with respect to the adjacent pole pieces of the two sets, in a known manner. In prior telephone transmitters of this type, the vibratory armature is pivotally mounted on brackets or the like carried by the field structure or by an external supporting member. While armature mountings of this character are reasonably satisfactory, they are expensive to manufacture and require delicate adjustments in order properly to align the armature with respect to the sets of adjacent pole pieces of the field structure.

Accordingly, it is an object of the present invention to provide an improved sound translating device of the type described having embodied therein a winding spool and armature assembly in which the armature is pivotally mounted on the winding spool and requires no external support.

Another object of the invention is to provide a telephone transmitter of the type described including an improved armature mounting member which is so constructed and arranged that the member is subjected to torsional strains when the armature is moved, whereby the movement of the armature is directly proportional to the operating force exerted thereon.

"A further object of the invention is to provide an improved winding spool and armature assembly which is of extremely simple and rugged construction, and which is compact and economical to manufacture.

In general, the objects as set forth above are attained in accordance with the present invention by providing an assembly of the character noted comprising a winding spool provided with a hollow body carrying spaced apart winding retaining heads, and an armature arranged within the hollow body and supported by the wall of the body for vibratory movements out of contact with the wall of the body of the winding spool. More specifically, the winding spool is formed of insulating material, while the armature is formed of fiat magnetic stock and provided with two transversely extending integral lugs, each of which is provided with a length of reduced crosssectional area. The lugs on the armature are rigidly supported in recesses formed in the wall of the body of the winding spool, whereby the armature is mounted for vibratory movements about an axis extending transversely of the winding spool and out of contact with the wall of the body of the winding spool; and the lengths of reduced cross-sectional area of the lugs on the armature are subjected to localized torsional strains, when the armature is moved.

The novel features believed to be characteristic of the invention are set forth the particularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawing, in which Figure 1 is a perspective view, partly broken away, of the winding spool and armature assembly embodying the present invention; Fig. 2 is a plan view, partly broken away, of the assembly shown in Fig. 1; Fig. 3 is a sectional view of the assembly, taken along the line 3-3 in Fig. 2; and Fig. 4 is a side elevational View, partly in section, of a telephone transmitter of the magnetic or sound powered type provided with a winding spool and armature assembly constructed in accordance with the present invention.

Referring now more particularly to Fig. 4 of the drawing, there is illustrated a sound translating device in the form of a telephone transmitter of the magnetic or sound powered type embodying a winding spool and armature assembly constructed in accordance with the present invention and comprising a field structure Ill and a winding spool and armature assembly II. The field structure Hi includes a permanent magnet l2 and two field members 13 and ll rigidly secured to the opposite ends thereof, the field member l3 being secured to the north pole of the permanent magnet l2, and the field member ll being secured to the south pole of the permanent magnet l2. The field members l3 and I3 are each provided with two pole pieces l5, l6 and II, l3, respectively, the pole pieces I! and I! being arranged in spaced apart relation adjacent each other and constituting a set, and the pole pieces I and I3 being arranged in a similar manner and constituting a set.

The assembly |l comprises a winding spool l9 provided with a body i3, carrying two spaced apart winding retaining heads It", and a winding 23 arranged-about the body I! between the retaining heads II". An armature 2| is pivotally mounted on the winding spool I9 in a manner more fully described subsequently and is supported by the winding spool Ia between the two sets of pole pieces, one end 2| of the armature 2| being disposed between the oppositely disposed pole faces of the set of adjacent pole pieces II and II and the other end 2| of the armature 2| being disposed between the oppositely disposed pole faces of the set of adjacent pole pieces I6 and II. The armature 2| is arranged within a longitudinally extending opening provided in the winding spool l3, and the ends 2 I and 2| there of are adapted to vibrate between the associated sets of adjacent pole pieces I5, I1 and I3, ll, respectively, and out of contact with the wall of the body of the winding spool IS. The end 2| of the armature 2| is provided with a projecting operating lug 22 having an opening therein in which one end of a rod 23 is secured, the rod 23 extending through an opening I3 formed in the field member l3, and the other end thereof being secured to a sound wave responsive diaphragm 24 supported about its periphery by suitable clamping means 25. Normally, the armature 2| occupies a position wherein the opposite ends thereof are disposed intermediate the adjacent pole pieces of the two sets and is adapted to be vibrated by the rod 23 when the diaphragm 23 is vibrated by sound waves impinging thereon. Thus, the movement of the armature 2| is controlled in accordance with the vibratory movements of the diaphragm 24, the vibratory movements of the diaphragm 24 corresponding to the vibrations of the air produced by the sound to be transmitted. As the armature 2| is moved in a clockwise direction about its pivot, the magnetic field of the field structure It traverses a path extending from the north pole of the permanent magnet |2 by way of the field member l3, the pole piece It, the armature 2|, the pole piece l1, and the field member I3 to the south pole of the permanent magnet l2. On the other hand, when the armature is moved in a counterclockwise direction about its pivot, the magnetic field of the field structure l traverses a path extending from the north pole of the permanent magnet |2 by way of the field member I3, the pole piece II, the armature 2|, the pole piece It, and the field member H to the south pole of the permanent magnet l2. Thus, during the vibratory movements of the armature 2|, the magnetic field of the field structure l0 traverses the armature 2| in opposite directions, causing a corresponding electromotive force to be generated in the winding 23 electromagnetically coupled thereto. The electromotive force generated in the winding 20 is transmitted to a distant point where it is utilized in a suitable receiver or other translating device to reproduce the sound transmitted in a well known manner.

The winding spool and armature assembly HA illustrated in Figs, 1, 2 and 3 comprises a winding spool formed of insulating material such as Bakelite and an armature 3| formed of fiat magnetic stock. The winding spool 30 comprises a body 32 carrying two spaced apart winding retaining heads 33, the body 32 of the winding spool 30 including top and bottom members 34 and 35, respectively, secured in spaced apart relation to two side members 33. The top and bottom members 3 and 35 extend between the winding retaining heads 33 and are preferably formed integral therewith; while the side members 33 extend between the winding retaining heads 33, being arranged in aligned openings 33" formed in the winding retaining heads 33. The armature 3| is provided with a longitudinally extending operating lug 3| and two transversely extending spaced apart lugs 31 intermediate the ends thereof. Each of the lugs 31 projects from one side of the armature 3| and is provided with a head 31' connected by a length 31 to the armature 3|, the length 3I being of reduced cross-sectional area. Each of the side members 33 of the body 32 of the winding spool 30 is provided with a recess 33 therein, which is adapted to receive the head 31" of one of the lugs 31.

In constructing the assembly IIA, the heads 31- of the lugs 31 on the armature 3| are inserted into the recesses 36' in the side members 36 and securely retained in place therein by an adhesive or the like. The assembled armature 3| and side members 33 are then inserted through the openings 33' provided in the winding retaining heads 33 and securely retained in place by an adhesive or the like.

The opposite ends of the armature 3| project through the openings formed in the winding retaining heads'33 and are protected against injury by projections 33 provided on the ends of the side members 36. The upper and lower members 34 and 35, respectively, of the body 32 are spaced a short distance from the upper and lower surfaces of the armature 3|, and the side members are spaced a short distance from the side surfaces of the armature 3| by the lengths 31 of the lugs 31. Thus, the body 32 of the wind ing spool 33 is hollow, the upper and lower members 34 and 33, respectively, and the side members 33 constituting a wall surrounding a narrow opening extending longitudinally therethrough; and the armature 3| is arranged within the opening in the body 32. The armature 3| is supported by the lugs 31 for vibratory movements out of contact with the wall of the body 32 and about an axis extending between the lugs 31 transversely of the winding spool 30, When the armature 3| is moved from its normal position, the lugs 31 are subjected to torsional strains, the strains being localized in the lengths of reduced cross-sectional area 3| of the lugs 31. This torsional mounting of the armature 3| is very advantageous, as it causes the armature 3| to be deflected an amount precisely corresponding to the force exerted upon the operating lug 3|", the deflection of the armature 3| being directly proportional to the force exerted upon the operating lug 3| over a wide range.

From the foregoing description it is apparent that a unitary winding spool and armature assembly for a telephone transmitter is provided, which is of rugged construction and comprises a minimum number of parts. Moreover, the assembly is compact and the pivotally mounted armature therein requires no external support. While the features 01 the present invention have been illustrated as being embodied in a telephone transmitter, it is apparent that they may be read ily embodied in a telephone receiver or other sound translating device.

While there has been described What is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is contemplated to cover in the appended claim all such modifications as fall within the true spirit and scope of the present invention.

What is claimed is:

An assembly for a sound translating device comprising, in combination, a winding spool formed of insulating material and including a longitudinally extending body and laterally ex tending winding-retaining heads carried on the opposite ends of said body, said body including top and bottom walls formed integral with said winding-retaining heads and side walls arranged in aligned openings provided in said winding-retaining heads, the walls of said body being arranged to define a narrow opening extending longitudinally through said body, and an armature formed of flat magnetic stock and provided with two transversely extending integral lugs, said armature being arranged in the opening in said body and the ends of said lugs being rigidly supported in aligned openings provided in the side walls of said body, whereby said armature is mounted for vibratory movements about an axis extending transversely of said winding spool and out of contact with the walls of said body and said lugs are subjected to torsional strains when said armature is moved.

HAROLD CHARLES PYE. 

